Ali actually boasted that he would fight on Mars in a long-lost 1966 interview that resurfaced recently as part of the PBS series "Blank on Blank."

"We'd estimate our time of getting there in about 10 years," Ali said in the interview. "I'll be 10 years older, but I'll still be in good shape. I expect the fight to go about 12 seconds."

Ali was joking, of course. But what would it really be like to box on Mars?

To reach the planet, it wouldn't take a decade. A journey to Mars takes about 150 to 300 days, according to Universe Today. Once you got there, your body would feel more like a "butterfly," even if you're not able to "float" like one here on Earth.